MRI of a lower extremity region other than a joint, done without contrast and then with contrast, often for a mass, infection, or tumor in the thigh, leg, or foot.
- Medicare
- $335.01
- Work RVU
- 2.1
- Global, days
- Region
- Multi-region
Documentation requirements
What must appear in the operative or office note to support the claim.
Source · Editorial brief grounded in 3 cited references ↓
- Clinical reason for a contrast study (mass, infection, tumor, postoperative change)
- Region imaged and laterality
- Contrast agent and dose, with both phases described
- Signed interpretation
- Prior authorization matching 73720
Applicable modifiers
Modifiers commonly billed with this code.
Source · AMA CPT modifier descriptors · CMS NCCI Policy Manual
What this code covers
Source · Editorial summary grounded in 3 cited references ↓
This is the non-joint lower extremity MRI with both a pre-contrast and post-contrast series. The region is the thigh, the lower leg, or the foot when the target is soft tissue or bone rather than a joint. Ortho practices order it for soft tissue masses, suspected osteomyelitis in a diabetic foot, abscess, and tumor follow-up. If the study centers on the hip, knee, or ankle joint, use the joint codes (73721 to 73723).
The foot is a frequent source of errors. A forefoot MRI for osteomyelitis is often coded as non-joint (73718 to 73720), while an ankle-centered study is a joint MRI. Read the protocol in the report and code from it.
Both phases have to be documented. If contrast was ordered but held for low GFR, the right code is 73718, and the authorization should be updated before billing. Commercial plans require prior authorization through their radiology benefit managers, and the request needs a clinical reason for contrast: infection, tumor, or postoperative change.
RVU & reimbursement
Component RVUs and Medicare national rate. Actual payment varies by GPCI locality.
Source · CMS Physician Fee Schedule, RVU26A · January 2026
Work RVU vs. total RVU
The work RVU (2.1) is the surgeon's own effort — the figure physician pay and productivity targets are built on. The total RVU (10.03) adds practice overhead and malpractice, and is what drives the Medicare payment below.
| Work RVU | 2.1 |
| Practice expense RVU | 7.78 |
| Malpractice RVU | 0.15 |
| Total RVU | 10.03 |
| Medicare national rate | $335.01 |
| Global period | days |
Payment by site of service
Medicare pays different rates by setting. HOPD typically pays substantially more than ASC for the same procedure.
Source · CMS OPPS Addendum B·ASC HCPCS payment rates·2026
| Setting | Medicare rate (national) |
|---|---|
Office (PFS non-facility) Procedure performed in physician's office | $335.01 |
HOPD (APC 5572) Hospital outpatient department | $356.43 |
Common denial reasons
The recurring reasons claims for CPT 73720 get rejected.
Source · Editorial brief grounded in CMS NCCI edits, AAOS coding appeals, and cited references ↓
- Joint-centered study billed as non-joint
- Contrast held but 73720 still billed
- Authorization issued for 73718
- No diagnosis that supports contrast
- Missing laterality or 26/TC split
Frequently asked questions
Source · Generated from the editorial pipeline, verified against 3 cited references ↓
01Is a foot MRI a joint or non-joint MRI?
02What code do I use if contrast was not given?
03Does 73720 need prior authorization?
Sources & references
Editorial content was developed using the following public sources.
Mira Scribe
Mira Scribe notes document the wound, exam, and lab context behind an MRI for suspected infection or a mass, which supports both the contrast and the authorization request.
See how Mira captures CPT 73720 documentation